Process for flame retarding fabrics

ABSTRACT

THE PRESENT INVENTION A PROCESS FOR FLAME RETARDING TEXTILES WHICH COMPRISES: (1) APPLYING TO A TEXTILE AN AQUEOUS SOLUTION CONSISTING OF (A) A PHOSPHONATE HAVING AT LEAST ONE CARBON-BONDED PRIMARY ALCOHOL GROUP, (B) DIMETHYLOLDIHYDROXYETHYLENE UREA, AND (C) A CURING CATALYST; AND (2) CURING THE PHOSPHONATE AND UREA ON THE TEXTILE AND THEREBY RENDERING THE TEXTILE FLAME RETARDANT.

United States Patent 3,746,572 PROCESS FOR FLAME RETARDING FABRICSEdward D. Weil, Hastings-on-Hudson, Ralph B. Fearing,

Bardonia, and Bernard J. Eisenberg, Nanuet, N.Y., assignors to StauiferChemical Company, New York,

.Y. N0 Drawing. Filed Feb. 23, 1971, Ser. No. 118,166 Int. Cl. C09d /18US. Cl. 117-136 34 Claims ABSTRACT OF THE DISCLOSURE The presentinvention provides a process for flame retarding textiles whichcomprises: (1) applying to a textile an aqueous solution consisting of(a) a phosphonate having at least one carbon-bonded primary alcoholgroup, (b) dimethyloldihydroxyethylene urea, and (c) a curing catalyst;and (2) curing the phosphonate and urea on the textile and therebyrendering the textile flame retardant.

This invention relates to a flame retardant textile finish. Moreparticularly, this invention relates to a process for flame retardingtextiles which comprises passing the textile through an aqueous paddingsolution containing a phosphonate having at least one carbon bondedprimary alcohol group, dimethyloldihydroxyethylene urea, and an acidcuring catalyst, and curing the treated textile to render the textileflame retardant. The present process is useful for flame retardingvarious types of textiles especially cellulosic including cotton andpolyester-cotton blends, viscose rayon, jute, and products made fromwood pulp.

By textile is meant hereinafter a fabric, filament, staple, or yarn, orproducts made therefrom, which may be woven or non-woven.

The flame retarding of textiles is of importance for improvement of thesafety characteristics of apparel, bedding, protective clothing, tentcloth, carpets, home furnishings, aircraft and automobile interiorfabrics, and industrial fabrics which may be woven, knitted, tufted andnon-woven.

There are various methods known for flame retarding textiles whichinclude the application of chlorinated paraifins with antimony oxide ortris-(dibromopropyl phosphate) plus a resinous binder; Such proceduresgenerally have the disadvantage of requiring the addition of a largeamount of solids with a resulting deleterious effect in the quality ofthe fabric. Furthermore, the resulting finishes are quite limited intheir durability to laundering and dry-cleaning. There have beenfinishes designed to be especially durable for cotton, for example,those based on tetrakis (hydroxymethyl) phosphonium chloride or onphosphonated N-methylolamides, but these have various limitations.

The tetrakis (hydroxymethyl) phosphonium chloride finishes have problemswith odor (formaldehyde and phosphine-like odors), and stiffness, i.e.,a poor hand. Attempts to overcome the hand problem by use of ammonia gasas a curing reagent have required equipment not generally available intextile mills. The phosphonated N-methylolamide finishes have been foundin mill practice to have problems of volatility, loss of phosphorus inthe pad-dry-cure afterwash cycle, and ultraviolet or thermal stabilitylimitations.

A further major limitation of the known finishes is theirineffectiveness on cotton-polyester blends, which are fabrics of greatcommercial importance.

[it is therefore a very important object of the present invention tomake available flame retardant finishes which can be used on natural andsynthetic textiles and fabrics, especially on cellulosics andcellulosic-synthetic blends, which involves the use of substantiallynon-toxic, lessvolatile phosphorus compounds, and which leaves thefabric with a soft tactile character (i.e., good hand) and good physicalstrength properties.

It is a further object to make available textile finishes which aredurable to both washing and drycleaning as well as being flameretardant.

Another object of the present invention is to make available finishesuseful for cotton-synthetics, especially cotton-polyester blends.

Another object of the present invention is to provide a process that canbe used with the primary polyol phosphonate to prevent undesirable colordevelopment on textiles. Those primary polyol phosphonates, such as 0,0-diethyl N,N-bis(2-hydroxyethy1) aminomethyl phosphonate, that maydevelop some color on curing can be whitened with a prolonged bleachingoperation. Prior to this invention, this whitening process involvedbleaching the treated textile for at least 20 minutes in a 5% solutionof sodium perborate at F.

According to the present invention, it has been unexpectedly found thatby adding sodium perborate to the padding solution and then padding andcuring the solu- .tion on the textile, the color is essentiallyprevented from forming on the textiles.

Also, according to the present invention, it has been unexpectedly foundthat dimethyloldihydroxyethylene urea provides good reactivity anddurability with the above primary polyol phosphonates whereasaminoplasts such as dimethylolethylene urea and methylolated melaminesdo not.

The present invention primarily provides a process for flame retardingmost textiles with a finish which can be thermally cured, a finish whichis durable when the textile is washed or dry cleaned, and which finishdoes not cause a color loss or undesired color development to the flameretardant textile.

The present flame retarding process comprises applying to a textile anaqueous solution containing a primary polyol phosphonate,dimethyloldihydroxyethylene urea, and an acid or latent acid catalyst.The aqueous bath may also contain optionally other aminoplast resins,softeners, surfactants, and bleaching agents. Then, the solution isdried on the fabric and the primary polyol phosphonate anddimethyloldihydroxyethylene urea are cured on the textile by heatingmeans to render the textile flame retardant. By curing, is meant theformation of a water-insoluble presumably polymeric finish by thecoreaction of the phosphorus alcohol and the dimethyloldihydroxyethyleneurea. Where cellulose is the substrate, chemical bonding to thecellulose may also be involved to an unknown degree.

The phosphorus reactant to be used in the process of the invention mustcontain at least one carbon-bonded primary alcohol group plus apentavalent phosphorus ester group. Secondary alcohol groups do not leadto durable finishes.

By a carbon-bonded primary alcohol group is meant a (HOCH group attachedto a carbon atom, which can be a methylene, methine, or quaternarycarbon atom. This structure is to be contrasted with methylol groupsattached to nitrogen or phosphorus, which have distinctly differentchemistry from the methylol groups on carbon.

In particular, the alcohol groups required by the process of theinvention are those which do not revert to formaldehyde in contrast tothe methylol groups such as N-methylol amides or tetrakis(hydroxymethyl) phosphonium salts which are known to be in equilibriumwith formaldehyde or which can release formaldehyde. Not being capableof releasing formaldehyde, the reactant alcohol compounds as used in theprocess of the invention do not lead to an undesirable degree ofcross-linking of the cellulosic fibers with ensuing stilf hand and lossof abrasion resistance or tear strength.

By a pentavalent phosphorus ester group is meant a structure of thegeneral formula:

R: (I) where R is a hydrocarbyl radical, preferably an aliphatic groupof 1 to 20 carbon atoms, which may be unsubstituted or substituted byhydroxy and/or halogen. The remaining two valences of the phosphorus aresatisfied by other organic radicals R and R such, for example, as alkyland alkoxy which may be unsubstituted or substituted by alkoxy,halogen'or hydroxy groups; hydroxypolyalkyleneoxy; phenyl; halophenyl;amino-substituted alkyl; -O-alkylene-O- or -'O-alkyleneoxyalkylene-O-bonded to the same or to another pentavalent phosphorus ester group;amino; alkyl-substituted amino or hydroxyalkylsubstituted amino, allwith the proviso that in at least one of the aforementioned groups therebe at least one carbonbonded primary alcohol group.

It is preferred, for reasons of improved durability, to have two or morecarbon-bonded primary alcohol groups in the phosphorus reagent, and forreasons of avoiding excessive cross linking, to have no more than sixsuch groups in the molecule.

Where the term alkyl, alkoxy, or alkylene is employed, it is preferredto have no more than eight carbon atoms in the radical, hereinafterdesignated lower alkyl, lower alkoxy, or lower alkylene.

The following compounds (Formula II) are examples of a subgroup ofuseful pentavalent phosphorus esters according to the present inventionhaving the formula:

wherein R and R are selected from the group consisting of lower alkyl,halogenated lower alkyl, lower alkoxyalkyl, lower hydroxyalkyl, loweralkoxy, lower hydroxyalkoxy, and halogenated lower alkoxy,hydroxypolyalkyleneoxy; and n is an integer from 1 to 6.

These compounds have good color and are generally convenient tosynthesize from low cost materials such as by reaction of ethylene oxidewith acid phosphates, pyrophosphates and phosphoric acid. Compounds ofthis class include the primary alcohols described in US. Pats.2,372,244; 3,402,132; 3,474,046; 3,474,047; and 3,487,- 030; and BritishPat. 1,082,013; which patents describe the synthesis and other uses forthese compounds.

An example of this subgroup of pentavalent phosphorus esters is thecompound:

o(CH2CHlo)nH HOCH: (III) where n has a value of from abo t 3 to 5. Thiscompound is sold under the trade name of Fyrol HMP, by the StaufferChemical Company.

A particularly useful group of phosphonates having carbon-bonded primaryalcohol groups and suitable for the present invention include variousphosphorus derivatives of diethanolamine having the general formula:

HoomoH,

HOCH CH, (IV) wherein R and R are alkyls, hydroxyalkyls, haloalkyls,alkoxyalkyls or hydroxyalkoxyalkyls of l to 6 carbon atoms, the terminiof an alkylene forming a six-membered ring or halogenated analogs, thetermini of an alkylene or alkyleneoxyalkylene bonded to a likephosphorus ester group, hydroxypolyoxyalkylene or hydroxysubstitutedanalogs thereof; R and R are hydrogen, lower alkyls of 1 to 6 carbonatoms; m is an integer from 0 to 2; and n is an integer from 0 to 1. 7

Examples of the phosphorus derivatives of this group include thefollowing:

HOCH CH; O OCH! N CHrl HOCH CH; OCH; (V) HOCHQOH O OCH(CH N-CHg-HOCIIZCHQ OCH(CH3) (VI) HOCH CH O OCH CHgCl N CH CH,

HOCH CH 0011 011 01 (VII) HOCHzCH: O OCHzCHgBr N C HzCHrd HOCHzCHgOCHzCHzBl (VIII) HOCHgCH: O O 00:11;

C H: C Hl-l HOOHICHI O 01H (IX) HOCHgCH: O O OCzH I ll N 0111-? HOCHQCH,OCgH (X) HOCHgGHg O OCH; CH:

-C Hrll C HOCHzCHr O C a CH:

HOCHzCH: [))OCH:CH2O),H

N CHr-P HOCHICH: (OCHICHI0)|1H (XII) where n is an integer from 11 to10.

| HOGHzCHaOCHzCHzOflOCHzCHzOCHzCHzOl!O CHzCHzO CHzCHzOH Nwmomon),momomon (XIII) CHI-O O H0---0\ ommomomom,

11 CHz-O (XIV) HOCHzCH: 0 00m CHIOH ll/ N-CH-P\ o HOCH CH. oofi, 011,011(XV) HOCHQCHQ O OCH;

I HO CHaC/g OCH (XVI) HOCHzCHa O O CzHb l| N-P HOCH: C O H; (XVII) HOCHCH O O CzHs N-CHg- HOCHzCg O CzHs (XVIII) These compounds constitute apreferred subgroup within the invention, since they generally impart ahigher degree of flame retardance relative to their phosphorus content,than do the nonamine derived compounds within the broader scope of theinvention. Their synthesis and use for other purposes are described inU.S. Pats. 3,076,- 019; 3,457,333; and 3,294,710; and British Pat.1,178,718.

A narrow preferred subgroup of pentavalent phosphorus esters, because ofthe ease of their manufacture, stability, and good flame retardanteflicacy is:

HOCH CH (If/ORB N(CH2)m P HO CH CH 0R5 (XX) where m is an integer from 0to 2 and R and R are defined hereinabove.

A preferred group of pentavalent phosphorus esters, because of theirunusually favorable color, stability, and flame retardant efficacy, are:

where R and R can be the same or different and are selected from thegroup consisting of hydrogen, lower alkyl, lower hydroxyalkyl, lowerhaloalkyl and hydroxy with the proviso that no more than one of R and Rcan be hydroxy. The preferred lower alkyl group in the applicable alkyl,hydroxyalkyl or haloalkyl groups is the methyl radical.

This class of compounds, all of which are new compositions of matter,can be readily prepared by reacting the known cyclic phosphonate of2,2-dimethylpropane- 1,3-diol, or an appropriately substitutedderivative of the latter diol where it is desired to vary R and/or Rwith diethanolamine and formaldehyde in the manner described in U.S.Pat. No. 3,076,010. Alternatively, the diethanolamine and formaldehydemay be replaced in this reaction with hydroxyethyl oxazolidine.

In general, the conditions for this reaction involve adding thediethanolamine to the formaldehyde, with agitation, at a temperature inthe range of about 20-30 C. Thereafter, the cyclic phosphonate of2,2-dimethylpropane-1,3-diol, or a substituted derivative thereof, isintroduced with agitation at a temperature in the range of from about2090 C. This reaction is exothermic so that the mixture is held at thelatter temperature until all of the phosphonate has reacted. The desiredend product is then recovered by removal of water. Where hydroxyethyloxazolidine is used in place of the formaldehyde and diethanolamine, itis simply combined with the cyclic phosphonate under the above describedreaction conditions.

Exemplary of this preferred group of pentavalent phosphorus esters arethe compounds:

11001510111 0 O-CH! (XXII) CHz-O O CHz-O (XXIII) omon CHQOH (XXV) It mayalso be noted that the above described class of compounds can be used aspolyols in the preparation of polyesters and polyurethanes.

The most preferred phosphonate for use in the present invention becauseof its excellent flame retardant efiicacy is the compound:

0,0-diethyl N,N-bis(2-hydroxy ethyl) aminomethylphosphonate whichcompound is sold under the trade name Fyrol 6, by the Stautfer ChemicalCompany.

The process of the present invention is based upon the findin thatdimethyloldihydroxyethylene urea which cocured with a phosphoruscompound of the above-defined type, imparts durable flame retardancy tothe textile, good tactile quality (hand), and good physical strengthproperties.

The compound dimethyloldihydroxyethylene urea, hereinafter known asDMDHEU, has the structure:

HOCHQN/ NCHzOH HOCHOH--OH (XXV) and is well known in the textilefinishing art as a durable press finishing resin. DMDHEU is synthesizedby the reaction of glyoxal with urea followed by methylolation of theresultant dihydroxyethylene urea with formaldehyde. Similar materialssuch as dimethylolethylene urea exhibit poor durability with the abovedescribed primary alcohols.

The acid curing catalyst for the process of the present invention may beany compound which affords an acidic reaction at the curing temperature.Such catalysts include mineral acids such as hydrochloric andphosphoric, organic acids such as oxalic, citric, succinic, maleic,glycolic, chloroacetic, and trichloroacetic, toluenesulfonic, alkyl acidphosphates and the like. Also included are the salts of strong acidsWith relatively weak bases, for example zinc chloride, magnesiumchloride, ammonium chloride, ammonium phosphates, and aminehydrochlorides. Some typical amine hydrochlorides include2-amino-2-methylpropanol hydrochloride, sold under the trade nameCatalyst AC, by the Monsanto Chemical Company, and the alkanolaminehydrochloride sold as Catalyst X'RF, by the Millmaster Onyx Corporation.A preferred salt catalyst is a buffered zinc nitrate catalyst, soldunder the trade name Catalyst X-4, by the Sun Chemical Company.

It is to be understood that the above mentioned salts may be viewed aslatent acid catalysts, which do not have substantial acid properties atlow temperatures but which become acid, by hydrolysis or dissociation,atthe curing temperature of the phosphonate and DMDHEU on the textile.

The pH of the padding bath is preferably adjusted to a pH of betweenabout 3 and about 6.7 which in general requires the addition of an acid,such as HCl or preferably H PO which is less corrosive. This acid addedto adjust the pH can be considered all or part of the acid catalystrequired for the curing reaction.

In addition to the three requisite components of the padding bath to beused in the process of the invention, there are optional componentswhich may be added, as is well known in the art of textile finishing, toaccomplish particular objectives.

Although the process of the invention affords advantageous tactilequalities (hand), further embellishment may be achieved by the use ofsofteners. These may be, for example, fatty substances such asstearamides, or hydrophobic polymers such as polyethylene emulsions.

Another optional ingredient of the padding composition is a surfactant,or a wetting agent, to aid wetting and penetration of the fibers.Suitable surfactants include alkyl aryl sulfonates and polyoxyethylenederivatives of alkyl phenols (such as Triton X-100, a product of theRohm and Haas Company).

Another optional ingredient of the padding composition is an additionalaminoplast blending ingredient, over and above, but not in place of therequisite amount of DMDHEU. This optional ingredient may be used toincrease the degree of durable press character, to impart wet or drycrease angle recovery, and/or to enhance the degree of flame retardancy.Suitable supplementary aminoplast blending ingredients that may be usedinclude methylolureas, methylolmelarnines, methylolurons,methyloltriazones, urea, fatty acid amides, ethylene urea, acetamide,dimethyl hydroxymethylcarbamoylethylphosphomate and the methyl ethers ofthe above listed methylol compounds. The preferred supplementaryanimoplast blending ingredients include melamines sold by the AmericanCyanamid Corporation under the trade names: AerotexM-3-tris(methoxymethyl) melamine; Aerotex 23 Specia partially methylatedpentamethylolmelamine; and Aerotex UM-dimethylol melamine. Anotheruseful supplementary aminoplast blending ingredient is tris-(methylol)melamine sold under the trade name Resloom HU, by the MonsantoChemical Company.

Another optional ingredient of the padding bath is a peroxygen bleach.Although the process of the invention, without bleach or with a mildafter bleach gives quite acceptable color for many uses, We havediscovered that for critical applications where extreme whiteness isrequired, the inclusion of a peroxygen bleach, such as sodium perborate,in the padding bath is highly advantageous. This is a surprising findingwhich is not known in customary textile mill practice.

According to the present process it has also been found that for optimumresults between color and durability it is desirable to adjust the pH ofthe padding formulation containing sodium perborate to between about 5.0and about 6.7. However, for less critical applications where colorformation isof no concern we have found that in the absence of thesodium perborate, optimum durability to repeated laundering is achievedby adiusting the pH between 3 and 5.5.

The solvent most commonly employed for the process of the presentinvention is water, although it is possible to disperse and apply thereactants and curing catalyst in a non-aqueous solvent such astrichloroethylene, perchloroethylene, methylene chloride, methylchloroform, or the like. When such a non-aqueous solvent is used, it isoften found advantageous to employ enough water to swell the cellulosictextile fibers and thus allow efficient uptake of the reactants. Themixtures of reactants, water, and non-aqueous solvent can be renderedhomogeneous by the use of an emulsifier.

The average and preferred amounts (in percentages) by weight, of thevarious components that can make up the aqueous padding solution of thepresent invention are provided in Table I below.

The formulation illustrated below in Table I is representative of thepresent invention. The specific formulation used in treating textileswill depend on the specific end use performance properties and degree offlame re- 8 tardancy desired. This is illustrated in the subsequentexamples with cellulosic fabrics and polyester/cotton blends.

TABLE I.COMPOSITION OF FLAME RETARDANT AQUEOUS PADDING BATH SOLUTION Foroptimum results, it is preferred to have the ratio of the primary polyolphosphonate to DMDHEU, between about 3:1 and about 1:2.

Although this formulation provided in Table I above is sufiicient,additional nitrogen containing resins, i.e., an aminoplast resin in theamount of between 0 and about 30% may be added to further improve theflame retardancy, or for increasing the crease recovery properties ofthe treated material. However these supplementary aminoplasts such as amelamine type may not replace the DMDHEU required for the invention.

The aqueous padding solutions of the present invention are preparedsimply by adding the various components together in water. To facilitatesolution of the sodium perborate it may be desired to add the perborateto the above formulation already containing the acid for pH control.

The aqueous solution is placed in a suitable vessel. The fiame retardantfinish is conveniently applied to the fabric by dipping it into, orpassing it through the aqueous bath. The excess liquid is removed bypressing the treated fabric through squeeze rolls, and then the fabricis dried, the temperature being a matter of convenience and equipmentranging from ambient up to the curing temperature. The treated fabric isthen heated to cure the finish at temperatures from about C. to about180 C., and preferably from about C. to about C. These temperatures areused with reaction times ranging from a fraction of a minute to a day,or usually from about 1 to about 10 minutes, depending on temperatureused. During the curing of the solution on the fabric, the polyolphosphonate and aminoplast are reacted in situ on the fabric to form aflame retardant finish thereon.

In order to determine the quality and durability of the finish on thefabric, the treated samples are first subjected to a hot water washcycle in a conventional home washing machine with the water at about 140F. This is to simulate an after wash treatment in a textile mill. Inthis washing, no soap, detergent, or water hardener is added to theWashing cycle.

Then, the samples are subjected to five detergent home laundering cyclesin the same washing machine. to each of these cycles there is added astrong detergent such as Proctor and Gamble Corporations Tide XK, in theamount of about 50 grams, and 200 parts per million of water hardness(calculated as CaCO and 8 bath towels for ballast.

The treated fabric samples may also be tested for their durability bywashing them in a boiling aqueous soapsoda solution containing 0.5% soapand 0.2% soda ash (Na CO for about 3 hours.

After the treated fabric samples have been washed with water, and withdetergent, or with a soap and soda ash solution, the fabrics areevaluated for flame retardancy using any of the well known testprocedures described hereinbelow. Retention of phosphorus is alsomeasured on some fabrics using X-ray fluoroescence. The various flameretardance tests are described below:

Limiting Oxygen Index (LOI) The Limiting Oxygen Index (LOI) is a testused for quantitatively measuring the minimum amount of oxygen (in aoxygen-nitrogen mixture) required to sustain combustion. In this test,which is carried out as described in ASTM D-2863, the specimen isignited from the top, rather than the bottom, and the minimum amount ofoxygen required to sustain burning towards the bottom of the specimen isrecorded.

Most untreated cotton and blend fabrics require a minimum LOI of 17 to19% O to sustain burning and are considered quite flammable. In general,as reported in Sources & Resources, vol. 2, 1969/5, by R. E. Seaman,increasing the LOI to 21% appears to correlate with fabrics capable ofpassing the standard horizontal flame test (methenamine pill test) forcarpets. Increasing the LOI still further to about 26.5% 0 or greater,represents self-extinguishing properties in air for sample specimensignited from the bottom in a vertical flame test (i.e. the AATCC 34-1966flame test described below) which represents the most stringent testconditions commonly used.

In the standard test in air, if the textile is self extinguishing in thevertical position, it is acceptable for the most stringent application.If the textile is self-extinguishing in the position of a 45 angle, itis acceptable for many applications. However, if the textile is onlyselfextinguishing when in a horizontal position the finish is acceptablefor use only in less critical applications.

Modified SPI 45 angle flame test This is another recognized flametesting procedure which is considered more severe than the standardAATCC 33-1966-45 angle test because it entails forced ignition. In thistest, like the AATCC 33-1966 flame test, the fabric sample is placed ata 45 angle but the sample is burned or ignited under conditions offorced ignition rather than using a one second timed ignition. Forexample, an untreated (65/35%) polyester/cotton fabric will pass the AATCC 33-1966-45 angle test whereas it fails to pass the Modified SPI 45angle test. In the latter case the untreated fabric will burn entirely.

Vertical flame testAATCC 34-1966 In this test, the fabric is suspendedvertically with the base of the fabric in. above a bunsen burner havinga flame height of 1% inches. The flame is held under the sample for 12seconds and then withdrawn. Char length is then measured in a standardmanner. Char length is the length in inches of charred fabric measuredfrom the base of the fabric upward. Accordingly, a short char length of5 to 7 inches indicates a good flame retardancy; Whereas a char lengthof to inches indicates a lower degree of flame retardancy of the treatedfabric and is not acceptable for most applications.

The present invention will be more fully and completely understood bythe following examples.

The following terms, as used herein and in the examples have thefollowing meanings:

5 DWThe fabric sample has been given one hot water wash cycle, and fivedetergent wash cycles.

3.2 oz./yd. -This is a light weight material weighing 3.2 ounces persquare yard. Light weight fabrics are generally more difiicult to flameretard than heavier weight fabrics.

8 oz./yd. This is a heavier weight material weighing 8 ounces per squareyard.

Add-on (percent)This indicates the percent increase in weight of the drysolids applied to the treated fabric based on the weight of theuntreated fabric.

OWFThis is used with the term percent add-on, and is defined as on theweight of the fabric. For example, add-on OWF is equal to 20% solidsapplied based on the weight of the fabric.

The components utilized in the following examples and tables are setforth in quantities by weight percent of solids or active ingredients.

10 EXAMPLE 1 A 2.6 ounce per square yard polyester/cotton (65/ 35%)fabric was padded through an aqueous bath containing the followingsolids or active ingredients: 30 percent of 0,0-diethylN,N-'bis-(2-hydroxyethyl) aminomethylphosphonate (Fyrol 6), 13.5 percentof dimethyloldihydroxyethyleneurea (DMDHEU), 1 percent of a softener, apolyethylene emulsion, and 1 percent of zinc nitrate (Catalyst X-4). ThepH of the aqueous bath was adjusted to about 5.0 with HCl.

The fabric after being passed through the aqueous bath, was dried for 5minutes at a temperature of about 230 F and cured 5 minutes at about 325F.

The percent dry add-on was calculated to be 27% based on the weight ofthe untreated fabric. After a one hot water wash, and five detergentWash cycles, the treated fabric was found to be self-extinguishing whenmeasured by the Modified SPI-45 angle flame test.

The same fabric untreated burned completely. The LOI of the fabric afterthe detergent launderings was 24%. The hand of the fabric was soft andflexible.

EXAMPLE 2 A 3.2 oz./yd. cotton print cloth was padded through an aqueousbath containing the following solids or active ingredients: 25 percentof 0,0-diethyl N,N-bis(2-hydroxyethyl aminomethylphosphonate (Fyrol 6),11.2 percent of DMDHEU, 15 percent Resloom HP, 1 percent part ofCatalyst AC, 2.5 percent of phosphoric acid, and 5 percent of sodiumperborate. The pH of the aqueous bath was 5.8. The dry add-on afterdrying 5 minutes at 230 F. and curing 5 minutes at 300 F., was 40% OWF.

Flame retardancy as measured by the vertical flame test (AATCC 34-1966)showed the treated fabric to be selfextinguishing with a 6 inch charlength before and after 5 detergent washes.

No apparent discoloration of the treated fabric was evident.

EXAMPLE 3 To compare the durability to laundering of finishes containingDMDHEU relative to a finish containing another aminoplast resin such astrimethylolmelamine, two aqueiaus padding baths were made up ofcompositions as folows:

Bath A: Percent by weight 21.6 DMDHEU 15 Zn(N0 catalyst 2 NaHSO(catalyst) 3 Polyoxyethylene ether (wetting agent) 0.3

Formula:

Bath B was similar but the DMDHEU was replaced by trimethylolmelamine.

Eight-ounce cotton cloth samples were padded in each bath, dried curedat and washed with water. Accelerated laundering was performed byboiling the swatches for 3 hours in a 0.2% soda, 0.5% soap solution. Theswatch treated with bath composition (A) was found to have 0.9%phosphorus and was self extinguishing, whereas the swatch treated withbath composition (B had only 0.27% phosphorus.

EXAMPLE 4 A 3.2 oz./yd. cotton print cloth was apdded through anaqueousbath containing the following solids or act1v1ty: 30% 0,0-diethylN,N-bis(2-hydroxyethyl)aminomethylphosphonate, 12% of dimethylolethyleneurea, 1% Catalyst X-4, and 0.5% Titon X-l00 with the pH of theformulation adjusted to 5.1 with HCl. The applied solids was 17.7% OWF.

parts of sodium perborate, the color was improved considerably andessentially non-existent at the higher pH of 6.6, as in Example 27.Residual color from Example 27 was removed after soaking the sample for1 minute 14 propanediol and diethyl phosphite are heated at 100 C. overa period of 2 days while removing the ethanol byproduct so as to yield aviscous liquid phosphonate having the formula:

in a 5% solution of sodium perborate at 180 F. 5

Example 29, which was formulated at a pH of 6 f E /CH2BT and cured onthe fabric at 150 C., was found to have HP o exgtellienii color, highdegree of flame retardancy and a \OmBr so I n I n I n In Table IIIbelow, additional Examples 30 through 10 Th1 lntermcdlate 18 thentreated W1th an equimolar 36 are provided to illustrate the durableflame retardant q y 0f py f y yl oxfllolldlne Whlle under aglta'properties with the use of other primary polyol phostron and whilebemgmamtalned at a temperature below phonates in combination withdimethyloldihydroxyethyly Yleldlng h Compound Whose formula ene urea(DMDHEU). As in Examples 6 through 29 of depicted hereinabove. This endproduct had the follow- Table II, the examples in Table II contain about0.5 15 g Y Found! part of active Triton X-100 wetting agent.Theoretical: Br=36.8%, N=3.22%, P=7.13%.

TABLE III Examples 30 31 32 a3 34 as HO PONCHOH1 30 odnioiiznsgzdmdrioionimozrnomz 30 so 30 [(OH;)2CHO];P(O)CHZN(C2H4OH)Z(czgsfprg(g)ggzg%g?rg%g;onu 30 i rirfini ir 2 z 4 13.5 13.5 13.5 13.513.5 13.5 13.5 Tn's(methoxymethyb 8 8 Catalyst (ii-M 1 1 1 1 1 1 233 H01H01 HCl H01 HC1H3PO4 H01 p 5.5 5.0 5.0 5.0 6.0 5 5 grion (percent 3128.6 21 27.6 27.6 40 40 26.3 23.3 29.0 27.5 27.5fiiififil'iivlfiii'.23123111111111:111212111111: 253 29. 8 23.1 25.623.4 26.4 25.8

To illustrate the connection in flame retardancy be- EXAMPLE 38 tweenLOI and vertical char length, some samples were This example illustratesthe preparation of: also tested by the vertical flame test, AATCC34-1966, 0 HOCH CH 0 O CH CH before and after 5 detergent washings. Thechar length 1 of samples of the various Examples tabulated below in N H=/O\ Table IV, further illustrates the relationship described HOCHZCH, OCHl CH hereinabove.

As can be seen from the results of these various examples the retentionof the char length after washing is not greatly affected.

In addition to providing flame retardancy, durability and good color oftreated textiles, it is also intended to provide a soft hand. Primarypolyol phosphonates reacted with 12 parts of a melamine type resinresult in a rather firm hand. However, similar fabrics containing 13.5parts of DMDHEU or a blend of about 11 to 13.5 parts of DMDHEU and amelamine resin as in Example 29 result in finished fabrics with a softhand.

EXAMPLE 37 This example illustrates the preparation of:

HOCH CH, O-CH, CH Br NCH HOCH G,

Equimolar proportions of 2,2-bis-bromomethyl-l,3-

A total of 234 grams of hydroxyethyl oxazolidine is placed into areactor to which there is then slowly added, under agitation, a total of310 grams of the cyclic phosphonate of 2,2-dimethylpropane-1,3-diol. Thesystem reached a temperature of 53-54 C. and the reaction was complete,in 2 /2 hours. The resulting product is obtained in a purity of aboutand has a refractive index n 1=1.4900.

EXAMPLE 39 This example illustrates the preparation of:

HO GHzCHz O O-CH: OH

A total of 224 grams of hydroxyethyl oxazolidine is heated to 60 C.whereupon 274 grams of the cyclic phosphonate of glycerol are slowlyadded with agitation. The system is cooled to maintain its temperatureat 60- 70 C. The reaction is complete after a total of about two hoursand the resulting reaction product contained a substantial proportion ofthe above described compound along with some linear dimers or polyestersthereof.

It is apparent that many modifications and variations of the inventionas hereinbefore set forth may be made without departing from the spiritand scope thereof; and therefore, only such limitations should beimposed as are indicated in the appended claims.

What is claimed is:

1. A process for flame retarding textiles which comprises:

(a) applying on a textile, an aqueous solution containing 1) apentavalent phosphorus ester having at least one carbon-bonded primaryalcohol group, (2) dimethyloldihydroxyethylene urea, and (3) an acidcuring catalyst; wherein the phosphorus ester anddimethyloldihydroxyethylene urea are included in said aqueous solutionin a ratio of the ester to the urea of between about 3:1 to about 1:2,and (b) curing the pentavalent phosphorus ester and saiddirnethylolhydroxyethylene urea on said textile so as to effect thecuring of the ester and the dimethylolhydroxyethylene urea with oneanother in situ on said textile to render the fabric flame retardant.

2. A process according to claim 1 wherein the phosphorus ester is:0,0-diethyl N,N-bis(2-hydroxyethyl) aminomethyl phosphonate.

3. A process according to claim 1 wherein the phosphorus ester has thestructure:

i=-OR Rf wherein R is a hydrocarbyl radical unsubstituted or substitutedby hydroxy and/or a halogen; and R and R are organic radicals selectedfrom the group consisting of alkyl and alkoxy which can be unsubstitutedor substituted by alkoxy, halogen or hydroxy; hydroxypolyalkyleneoxy;phenyl; halophenyl; amino-substituted alkyl; or, O-alkylene-O- orO-alkyleneoxyalkylene-O bonded to the same or to another pentavalentphosphorus ester group, amino, alkyl-substituted amino orhydroxyalkyl-substituted amino, with the proviso that in theaforementioned groups there be at least one carbon-bonded primaryalcohol group.

4. A process according to claim 1 wherein the phosphorus ester has thestructure:

wherein R and R are selected from the group consisting of lower alkyl,halogenated lower alkyl, lower alkoxyalkyl, lower hydroxyalkyl, loweralkoxy, lower hydroxyalkoxy, hydroxypolyalkyleneoxy and halogenatedlower alkoxy; and n is an integer from 1 to 6.

5. A process according to claim 1 wherein the phosphorus ester has thestructure:

HO 011,03; R1 (")/OR| N PG HOCHzC Rs in 0R5 wherein R and R are alkyls,hydroxyalkyls, alkoxyalkyls or hydroxyalkoxyalkyls of l to 6 carbonatoms, the termini of an alkylene forming a six-membered ring or ahalogenated analog, the termini of an alkylene or alkyleneoxyalkylenebonded to a like phosphorus ester group, hydroxypolyoxyalkylene or ahydroxy substituted analog thereof; R and R are hydrogen, or loweralkyls of 1 to 6 carbon atoms; m is an integer of 0 to 2; and n is aninteger from 0 to l.

6. A process according to claim 1 wherein the phosphorus ester has thestructure:

HO CHzCHfl N(CH2)m1 HOCHiOH,

ORI

HOCH, O O 02 NCH HOCH, 0 CI I 8. A process according to claim 1 whereinthe phosphorus ester has the structure:

HOCH CH OI/OCE: R

N-CHa-i\ /C\ HOCH OH, OCH, Rm

where R and R can be the same or difierent and are selected from thegroup consisting of hydrogen, lower alkyl, lower hydroxyalkyl, lowerhaloalkyl and hydroxy with the proviso that no more than one of R and Rcan be hydroxy.

9. A process according to claim 1 wherein the phosphorus ester has thestructure:

10. A process according to claim 1 wherein the phos phorus ester has thestructure:

11. A process according to claim 1 wherein the phosphorus ester has thestructure:

12. A process according to claim 1 wherein the phosphorus ester has thestructure:

13. A process according to claim 1 wherein said aqueous solution alsocontains sodium perborate.

14. A process according to claim 1 wherein the acid curing catalyst isselected from the group consisting of zinc nitrate, 2 amino 2methylpropanol hydrochloride, zinc chloride and magnesium chloride.

15. A process according to claim 1 wherein the phosphorus ester anddimethyloldihydroxyethylene urea are cured at a temperature rangingbetween 200 and 400 F. for a period of about 3 to about 10 minutes.

16. A process according to claim 1 wherein a sufiicient amount of saidacid curing catalyst is added to the aqueous solution to adjust the pHthereof to between about 3 and about 6%.

17. A process according to claim 8 wherein the phosphorus ester has thestructure:

18. The process of claim 14, wherein said acid catalyst is zinc nitrate.

19. A flame retardant textile comprising a textile having cured thereonthe reaction product of: (1) a pentavalent phosphorus ester having atleast one carbonbonded primary alcohol group; (2)dimethyloldihydroxyethylene urea; and, (3) an acid curing catalyst,wherein said phosphorus ester and said dimethyloldihydroxyethylene ureaare present in said reaction product in a ratio of the ester to the ureaof between about 3:1 to about 1:2.

20. The textile of claim 19, wherein said phosphorus ester is:0,0-diethyl N,N-bis(2-hydroxyethyl) aminomethyl phosphonate.

21. The textile of claim 19, wherein the phosphorus ester has thestructure:

wherein R is a hydrocarbyl radical unsubstituted or substituted byhydroxy and/or a halogen; and R and R are organic radicals selected fromthe group consisting of alkyl and alkoxy, which can be unsubstitutedor.substituted by alkoxy, halogen or hydroxy; hydroxypolyalkyleneoxy;phenyl; halophenyl; amino-substituted alkyl; or, -O-alkylene-O- orO-alkyleneoxyalkylene-O bonded to the same or to another pentavalentphosphorus ester group, amino, alkyl-substituted amino orhydroxyalkylsubstituted amino, with the proviso that in theaforementioned groups there be at least one carbon-bonded primaryalcohol group.

22. The textile of claim 19, wherein the phosphorus ester has thestructure:

wherein R and R are selected from the group consisting of lower alkyl,halogenated lower alkyl, lower alkoxyalkyl, lower alkyleneoxy andhalogenated lower alkoxy; and n is an integer from 1 to 6.

23. The textile of claim 19, wherein the phosphorus ester has thestructure:

wherein R and R are alkyls, hydroxyalkyls, alkoxyalkyls orhydroxyalkoxyalkyls of 1 to 6 carbon atoms, the termini of an alkyleneforming a six-membered ring or a halogenated analog, the termini of analkylene or alkyleneoxyalkylene bonded to a like phosphorus ester group,hydroxypolyoxyalkylene or a hydroxy substituted analog thereof; R and Rare hydrogen, or lower alkyls of 1 to 6 carbon atoms; m is an integer ofto 2; and n is an integer from 0 to 1.

24. The textile of claim 19, wherein the phosphorus ester has thestructure:

HOCHZCH] fl) 0R0 N(CHz)m-P HOCHzC 1 5 0 CzHs HOCH CH, O OCH; R;

HOGH C OCH: R10

where R and R can be the same or different and are selected from thegroup consisting of hydrogen, lower alkyl, lower hydroxyalkyl, lowerhaloalkyl and hydroxy with the proviso that no more than one of R and Rcan be hydroxy.

27. The textile of claim 19, wherein the phosphorus ester has thestructure:

28. The textile of claim 19, wherein the phosphorus ester has thestructure:

29. The textile of claim 19, wherein the phosphorus ester has thestructure:

30. The textile of claim 19, wherein the phosphorus ester has thestructure:

31. The textile of claim 26, wherein the phosphorus ester has thestructure:

r-cH Nw flloH),

32. The textile of claim 20, wherein sodium perborate residues are alsopresent in said reaction product.

33. The textile of claim 20, wherein said acid catalyst is selected fromthe group consisting of zinc nitrate, 2- amino-Z-methylpropanolhydrochloride, zinc chloride and magnesium chloride.

34. The textile of claim 33, wherein said catalyst is zinc nitrate.

References Cited UNITED STATES PATENTS 3,179,522 4/1965 Temin 117-136 X3,459,716 8/1969 Schaefer et a1. 117-143 R 3,076,010 1/ 1963 Beck et al260945 3,294,710 12/1966 Rosenberg et a1. 260-970 UX 3,457,333 7/1969Price 260-945 3,220,869 11/1965 Ruemens et a1. 117139.4 X 3,192,2426/1965 Birum 117-136 X 3,420,702 1/ 1969 Spangler 117139.4

WILLIAM D. MARTIN, Primary Examiner T. G. DAVIS, Assistant Examiner US.Cl. X.R. 117138.8 F, 143 A 33331 111mm) S'lA'iEZS lwim'z. OFFICECER'LHZCA'US OF CORREC'JLION Patent 130, 3:7 :57 Dated y 7:

Inventor) Edward D, Weil, Ralph B. Fearing & Bernard J. Eisenberg .It iscertified that error appears in the ahoveddcntified.patent and that saidLetters Patent are hereby corrected as shown below:

golumn 5, line 20, the number "019'" should read O1O- Column 6, line 5,FORMULA XXIV should appear as follows:

- HOCHZCHZ 0 o- CH2 11 3]:

" Hocn cn 0-" CH 4 'fCH Br .Column 10, ll, [line 69, .the Word'fap'dded" should a read padded line 73, the word "Titon" should 'read--.'Tri ton.--.

Column 12, TABLE 11, line 15', the word "Add-1n" should read Addn line18', under Example l, th numher "B l-.7" should read '24.?

line 18, under Example 17, .thenumber "26.9"

should read 26.8 line 21, under Example 6,;the number "0.5" should read1-05,

Column 15, TABLE .111, line 14, the word "(percent' should t a read(percent)- .1-

Column 15, Claim 1, line 9, the word "ylolhydroxyethylene" should readyloldihydroxyethylene -line 10;

the Word "dimethylolhyw" should read dimethyloldihy- Claim 5, line 27,the word "O-alkyl-" should read -O-alkyl- 4 ro-wso 5 v m T I CER'lil*LCA i I; OF CUliRlsC l LON Patent No. 5,746,572 Dated July 1975 1 Well,ph Fearlng & Bernard J. 'Elsenberg Page 2 I It is certified that errorappears in the above-identifiedpatent and that said Letters Patent arehereby corrected as shown below:

in Column 1?, Claim 22, line 20, after "lower" (first Occurrence) inserhydrox'yal'kyl, lower alkoxy, lower hydroxyalkoxy,hydroxypolyalkyleneoxy line 20, delete the word "alkyleneoxy" 4 1 Column18, Claim 32, line; 58, the number "20"- sh oul'd read "l9 Claim 55,-line 40, .the number "20' should read 19 Signed and. sealed thie 19thday O E 'Y M- ($EAL) z I I v Attes't: 1 I H EDWARD MLFLETCHERJR. c.MARSHALL 'DANN 'Attesting Officer Commissloner of Patents

